Air-fuel mixer for internal combustion engine



March 8, 1960 R. BAVERSTOCK 2,927,843

AIR-FUEL MIXER FOR INTERNAL COMBUSTION ENGINE Filed Nov. 4, 1957 4 Sheets-Sheet 1 1 72 HIE-:2 .Z. 75 G5 8/67/6 20 514/585706'5, a5 INVENTOR.

March 8, 1960 AIR-FUEL MIXER FOR INTERNAL COMBUSTION ENGINE Filed NOV. 4, 1957 I OF 1 IIII R. BAVERSTOCVK 4 Sheets-Sheet 2 NTOR.

March 8, 1960 R. BAVERSTOCK AIR-FUEL MIXER FOR INTERNAL COMBUSTION ENGINE 4 Sheets-Sheet 3 Filed NOV. 4, 1957 March 8, 1960 R. BAVERSTQCK AIR-FUEL MIXER FOR INTERNAL COMBUSTION ENGINE Filed Nov. 4, 1957 4 Sheets-Sheet 4 a. m. 9m Nm 6 g b] mu v E: sv on m 3 mm mw .m @v Q A V cm '5- g mm B R... mu 0N mm mm/ R V .m um mm .umm QN om 00 NW hm sm mm em W w 3 F N? H m OT 1 R. Q wTx INVENTOR.

ATTU/QA/EVS .-.lines 66 as shown inFigure 5. Figure. 7 is a view similar: to Figure 6 showing the ac- ..tion ofone. ofthecam elements. 1 I

N Figure 8is-a perspective view showing the under sidev of the air valve. member. a

AIR-FUEL MIXER FOR INTERNAL COMBUSTION ENGINE Richard Baverstock, North Long Beach, Calif., assignor, by direct and mesne assignments, to Imperial Machine Products (10., South Gate, .Califl, a corporation of California 1 Application November 4, 1957, Serial No. 694,392'

15 Claims. (Cl. 48-184)' This invention relates to gas mixing apparatus and is particularly directed to improvements in a device for supplying a mixture of gaseous fuel and air to an internal combustion engine.

An important objectof this vention is to provide a device for converting a gasoline engine to burnbutane or propane or natural gas or mixtures thereof.

Another object is to provide a mixer device which automatically regulates the mixture of fuel and air for all engine speeds.

Another object is to provide such a device which may be readily installed in the space normally occupied by the air cleaner and directly connected to the air intake of the carburetor. I

Another object is to provide a mixer devicehaving a novel air valve and fuel valve assembly operated-by a diaphragm subjected to differential pressures.

Another object is to providea fuel mixer device of this type having means for rendering the diaphragm and associated parts inoperative so that the engine'may be operated either on liquid fuel or gaseous fuel as desired;

Other and more detailed objects and advantages will appear hereinafter. f

In the drawings:

Figure l is a side elevation showing a preferred embodiment of this invention.

Figure 2 is a sectional elevation thereof.

Figure 3 is a sectional plan view taken substantially on the lines 33 as shown in Figure 2.." 3

Figure 4 is a sectional view similar to Figure -2-showing the air valve and fuel valve in fully opened position.

Figure 5 is a view of the underside of the device taken substantially on the lines55' as shown in Figure 2.

Figure 6 is a sectional detail taken substantially on the .Figure 9 is a sectional elevation'taken substantially on the lines 9 -9 as; shown in Figure 2.

Referring to the drawings, the housing generally designated 10 includes a base 11, spacerv ring 12, cover 13, an elbow 14 and anannular'shell 15. An adapter ring 16 is attached tov the base 11' by meansof threadedlfastener 17 and this ring rests onthe flange 18 ofthe upright tubular member'19 which constitutes part of a conventional carburetor 20. The usual butterfly type throttle valve 21 is provided in thetubular member 19 and opera ated by conventional means (not shown). The .carbu- 'retor communicates with the intake manifold 22 of a con-- ventional internal combustion engine (not shown).

I The base 11 is. provided with three upstanding bosses U i ed States Patent 2,927,848 Patented 'Mar. 8, 1 960 2' l 23 and through the spacer ring 12 and cover 13 to secure the parts in assembled relationship.

A flexible annular diaphragm 25 is clamped on its outer periphery between the cover 13 and spacer ring 12 and this diaphragm 25 has a central opening 26 through which a central projection 27 on the cover 13 depends. The inner portionof the diaphragm 25 is clamped to the upper surface '28 of the air valve member 29 by means of the back-up plate 30 and threaded fastenings 31. p This air valve member 29 moves vertically with the inner portion of the flexible diaphragm 25 and it is guided for vertical movement by means of a central axial rod 32. This rod is connected to the air valve member by threads 33 and the rod has an enlarged upper end 34 slidably received in a vertical bore 35. This bore 35 is provided within a boss 36 mounted within the elbow 14. The elbow has a central portion which is clamped to the cover 13 by means of the threaded fastenings 37. The downward'projection 27 on the cover 13 is provided with a central passage .38 for fuel. A fuel valve 39 has a central opening slidably received on the rod 32 and a coil spring 40 acts to hold 'the fuel valve 39 against the washer 41 and the rod en- A seat ring 45 encircles the air valve member 29 and is provided with a central cylindrical bore 46. This seat ring 45 is providedwith three radially projecting arms' -47 and at the other. end of each of these arms 47 there is provided a vertical post 48 which is mounted for sliding movement within vertical apertures 49 provided in the base 11. During normal operation of. the device, the lower surface 50 on the seat ring 45 rests on the cooperating surface 51 on the base 11. The posts 48 serve to maintain alignment between the cylindrical opening 46 in the seat ring 45 and the discharge opening 23a in the base 11. 7 Another function of the posts 48 is described hereinafter.

A flatannular valve ring 52 is looselymounted on the air valve member 29 near the upper end thereof and is supported by an annular shoulder 53. The valve ring 52 is adapted to rest on the surface 54 at the uppenend of the seat ring 45 when the valve member 29 is imits lowest position. A coil spring 55 encircles the projection 27 and is interposed between the back-up plate 31! and the cover 13. This spring 55 normally acts to'move the .-circumferentiall-y spaced on the under-side thereof and each of these bosses merges with a tapering outer surface 57 which extends between each of the bosses. Each boss has a downward opening aperture or part 58 which establishes communication from the chamber 43 within the air valve member 29 to the space within the discharge opening 24 in the base 11. The central portion of the valve member 29 is closed at the lower end by the bottom wall 60. A smooth curved outer surface between the positions or the bosses 56 is thus defined by the curved wall 57 and curved wall 61 on the bottom portion 60. Accordingly, when the air valve member 29 is raised upward to the dotted line position shown in Figure 2, the valve plate 52 is lifted away from the seat ring 45 and a smooth passage for flow of air inward from the space Thestrength of the spring aee' ness outside the seat ring 45 into the space 59 is provided, as shown by the arrow 69. This downward fiow of air within the seat ring 45 has an aspirating effect on gaseous fuel passing downward through the ports 58 from the chamber 43 of the air valve member 29.

' In Operation the supply of gasoline to thecarburetor is shut off and gaseous fuel such as butane is supplied under atmospheric pressure through the inlet conduit 65 and enters the space 42 within the elbow 14. Suction in the intake manifold 22 of the internal combustion engine reduces the pressure within the tubular member 19 above the throttle valve and within the space 59. Atmospheric air enters the shell around the lower peripheral edge thereof, passes through the filter 66, and enters the space 67 outside the seat ring 45. The pressure of the atmospheric air below the flexible diaphragm 25 applies an upward force to the diaphragm which is greater than the downward force of the spring 55 plus the gravity weight of themoving parts because the space 68 above the diaphragm 25 communicates with the space 59 through chamber 43 and ports 58 by way of the annular opening 26. The pressure above the diaphragm 25 is lower than the pressure below it whenever the engine is running, and the action of the diaphragm 25 is to lift the air valve member 29 relative to the seat ring 45, thereby to permit flow of air from the space 67 in the direction of the arrow 69 into the interior of the seat ring 45. The flow of air downward along the curved surfaces 57 and into the opening 24 and tubular member 19 causes an aspirating effect producing discharge of gaseous fuel through the ports 58. Thefuel is mixed thoroughly with the flowing air as it passes outof the mixer device and into the tubular member 19. a

As the air valve member '29 raises, it also raises the fuel valve cone 39 and hence reduces the restricting effect with the fuel passage 38 with the result that the rate of flow of gaseous fuel is increased. Accordingly, up-

' wa'rd movement of the air valve 29 serves to increase both the rate of flow of air and gaseous fuel in the proper proportions. The action of the diaphragm 25 is to increase the flow of combustible mixture to the engine as the throttle 21 is turned toward open position. The reduction in pressure in the member 19 above the throttle valve 21 becomes more pronounced as the throttle valve opens, with corresponding increase in the extent'of movement of the diaphragm 25.

A screw plug 70 is mounted on the elbow 14 and projects into the space 42 to restrict the flow of gaseous fuel to any desired extent. The plug is fixed in adjusted position by means of the lock nut 71 and is covered by the protector 72. Another plug 73 is removably mounted on the elbow directly above the bore 35 and serves only to close an access opening for inserting a screw driver or other tool into the'bore for the purpose of adjusting the position of the threaded rod 32 with respect to the air valve member 29.

The plate valve 52 is provided in order that the fuel 'valve 39 may seat tightly and close ofi all flow of gaseous fuel when the diaphragm 29 is in its lowermost position. The plate valve 52 strikes the upper surface 54 on the seat ring 45 before the fuel valve 39 completely closes the passage 38.

Removable plug 74 closes an opening which may be used when required to connect one side of a pressure regulator diaphragm (not shown) with the space 67 within the mixer device. Normally a pressure regulator of some type is required for supplying gaseous fuel such as butane at atmospheric pressure and a regulator device of conventional type for accomplishing that purpose may employ a diaphragm having one side exposed to the atmospheric pressure. In certain instances, it is desirable to balance the atmospheric pressure againstthat diaphragm with the pressure existing within the space 67. I In some instances, it is desirable to operate an 'internal combustion engine on eithcr' q usl 3 I have provided means for rendering the mixer device inoperable and to arrange the internal parts so that a free flow of air may be obtained directly from the air filter 66 into the tubular member 19. As shown in the drawings, this means includes cam mechanism for raising the seat ring 45 to the inoperative position shown in Figure 4. I provide a cam ring which has a horizontal portion 81 mounted to turn freely in a groove 82 provided on the base 11 adjacent the adapter ring 16. The cam ring 80 is also provided with downward extendin'g arcuate cam elements 82a, having camming surfaces 83 engaging head elements 84 provided on the other ends of the vertical posts 48. An actuating arm 85 is fixed on the cam ring 80 and arranged tobe moved through an arc of travel by means of a cable 86 clamped to the arm by means of the terminal fitting 87 and set screw 88. When the cable is actuated, the cam ring 80 is turned through an arc to bring the cam elements 82 from the inoperative position shown in Figure 6 to the active position shown in Figure 7. This action serves to lift the vertical posts 48 against the action of the springs 89 to elevate the seat ring 45 to the position shown in Figure 4.

In this position, air flows from the space 67 under the seat ring 45 and between the surfaces 50 and 51 into the space 59 and into the interior of the tubular member 19. The supply of gaseous fuel is shut oif by means (not shown) upstream from the conduit 65 and liquid fuel is supplied to the carburetor 20 by conventional means (not shown). When the seat ring 45 is in the elevated position as shown in Figure 4, the engine operates on liquid fuel passing through the carburetor in the conventional manner.

Having fully described'my invention, it is to be understood that I do not wish to be limited by the details herein set forthbut myinventionis of the full scope of theappended claims.

I claim:

1. In a gas mixing device, the combination of: a housing having a discharge opening, a stationary annular seat ring on the housing communicating with the opening, a movable valve member having means thereon adapted to form a seal with the seat ring, means mounting the valve member for axial movement relative to the seat ring to provide an annular flow passage therebetween, the housing having an axial passage, a valve element restricting flow through the passage, and fluid-pressure responsive means for causing simultaneous opening movement of the valve member and the valve element upon reduction .form a seal with the seat ring, means mounting the valve member for axial movement relative to the seat ring to provide anannular flow passage therebetween, the hous- 'ing having an axialpassage, a 'valve element restricting flow through the'passage, fluid-pressure responsive means for causing simultaneous movement of the valve member and the valve element, the latter said means including-a differential pressure device, having. opposed faces subjected to pressures inside and outside said ring, whereby reduction in pressure within the discharge opening acts to move the valve element and valve member in directions to increase flow.

3. In an air-fuel mixer device,'the combination of; a

, housing havin'g a dischargeopening, astationary annular seat ringon the housing communicating with the openi temst e a e rs were h in a m charnbe1 and having means thereon adaptedto form a sear with the seat ring, means mounting the air'valve member for axial movement relative to theseat ringto providean annular flow pa'ssage for air therebetween, the

housing having'an axial fuel passage communicating with a ar-ass the chamber within the air valve member, a valve element restricting flow through the fuel-passage,- fluid-pressure responsive means for causing simultaneous movement of {the airvalve member and the fuel valve element, and port means in the air valve member for discharging gaseous fuel into the interior of said seat ring. I

4. An air-fuel mixer device forattachmentto the air .inlet of a carburetor comprising in combination; a housing having a discharge opening to communicate with said air inlet, astationary annular seat ring on the housing communicating with the discharge opening, a movable air valve member having means thereon adapted to form a seal with the seat ring, means ,mounting the airvalve member .for axial movemenh'relative to the seat ring to provide an annular flow passage for air into the discharge opening, the housinghaving anjaxial passage for gaseous fuel, a valve element restrictingflow through the passage,

rneans for connecting the air valve member and the fuel .valve element for axial movement as a unit, andfluidpressure responsive means for moving the air valvem ember and the fuel valve element toward open position in response to reduction of pressure within said discharge opening.

5. In an air-fuel mixer device, the combination of: a housing having 'a discharge opening, a stationary annular seat ring on the housing communicating with the 'opening, a movable air valve member having an internal chamber and having means thereon adapted to form a seal with the seat ring, means mounting the air valve member for axial movement 'relative'to the seat ring to 'provide an annular flow passage for air therebetween, the

,housing having an axial projectioncontaining a fuel passage communicating with the chamber within the air valve member, a valve element restricting flow through the passage,means for causing simultaneous movement of the air valve member and the fuel valve element, the latter said means including an annular flexible diaphragm encircling said projection and'connected to the air valve member, means for subjecting opposed faces ofthe flexi- .ble diaphragm to pressure inside, and outside'of the seat,

'ring, respectively, and ports in the air valve member for discharging gaseous fuel into the interior of said seat ring.

6. Apparatus for supplying a mixture of atmospheric air and gaseous fuel to operate an internal combustion engine, comprising in combination: a housing having a discharge opening, a stationary annular seat ring on the housing communicating with the discharge opening, a movable air valve member encircled by the seat ring, means ,on the air'valve member adapted to form a seal with the seat ring, means mounting the air valve member for axial movement relative to the seat ring to provide an annular flow passage for air into the discharge opening, the latter said means including a vertical rod slidably mounted upon the housing, the housing having an axial fuel passage communicating with the discharge opening,

the rod extending centrally through said fuel passage, a

valve element on the rod restricting flow through the fuel passage, and means responsive to a reduction in pressure in the discharge opening for lifting the air valve member and fuel valve element to increase the rate of flow of air and gaseous fuel.

7. Apparatus for supplying a mixture of atmospheric air and gaseous fuel to operate an internal combustion engine, comprising in combination: a housing having a discharge opening, a stationary annular seat ring on the housing communicating with the discharge opening, a movable air valve member extending coaxially into and encircled by the seat ring, means on the air valve member adapted to form a seal with the upper end of the seat ring, means mounting the air valve member for axial movement relative to the seat ring to provide an annular flow passage for air into the discharge opening, the housing having an axial fuel passage, means in the air valve member establishing communication between the .fuel' passage and the discharge opening, a valve element restricting flow through the passage, means connecting the ,fuel valve element and the air valve member for movement as a unit, and means responsive to a reduction in pressure in the discharge opening for lifting the air valve member and fuel valve element to increase the rate of flow of air and gaseous fuel. a

8. Apparatus for supplying a mixture of-atmospheric air and gaseous fuel to operate an internal combustion engine, comprising in combination: a housing, having a discharge opening, a stationary annular seat ring on the housing communicating with the discharge opening, a movable air valve member extending coaxially into and encircled by the seat ring, the air valve member having an internal chamber, means on the air valve member adapted to form a seal with the upper end of the seat ring, means on the housing mounting the air valve memher for axial movement relative to the seat ring to provide an annular flow passage for air into the discharge opening, the latter said means including a vertical rod slidably mounted upon the housing, the housing having an axial fuel passage communicating with the chamber within the air valve member, the rod extending centrally through said fuel passage, a valve element on the rod restricting flow through the fuel passage, ports inthe air valve member for discharging gaseous fuel into thedischarge opening, and means responsive tofa reduction in pressure within the discharge opening for lifting the air valve member and fuel valve element to increase the rate of flow of air and gaseous fuel.

9. An air-fuel mixer device for attachment to the air inlet of p a carburetor, comprising in combination: a housing having a discharge opening, an annular seat ring communicating with the discharge opening, a movable air valve member adapted to form a, seal with thes'eat ring, diiferential pressure means in thehousing for moving the air valve member axially relative to the seat ring toprovide an annular flow passage for air therebetween, I fuel valve means within the housing operatively y connected for actuation by movement of the air valvemernber and'discharging into the air flow passage,the differential pressure means including a diaphragm having an upper face subjected to pressure in the discharge opening and a lower face subjected to atmospheric air pressure, and mechanical means on the housing for raisving the seat ring axially relative to the housing to provide a direct passage for atmospheric air to said discharge opening.

10. An air-fuel mixer device for attachment to the air inlet of a carburetor, comprising in combination: a

housing having a discharge opening, an annular seat ring communicating with the discharge opening, a movable air valve member positioned coaxially of the seat ring, means on the air valve member adapted to'form a seal with the seat ring, means on the housing mounting the air valve member for axial movement relative to the seat ring to provide an annular flow passage for air therebetween, fuel valve means within the housing operatively connected for actuation by movement of the air valve member, a diaphragm connected to actuate the air valve member, the diaphragm having an'upper face subjected to pressure in the discharge opening and a lower face subjected to atmospheric air pressure, and mechanical means for raising the seat ring axially relative to the housing to render the diaphragm inoperable and to provide a direct passage for atmospheric air to said games are ta-arenas an annular new passa e for air the-ref'betw'een, fuel valve means within the housing operatively connected for actuation by movement of the air valve member and discharging into the air flow passage, the difierential pressure means including a diaphragm having an upper face subjected to pressure in the discharge opening and a lower face subjected to atmospheric air pressure, means including a plurality of vertical posts sli'dably mounted upon the housing for supporting the seat ring in position, a horizontal cam ring mounted to turn on the housing, and cam elements onthering en- "gaging the posts for raising the seat ring axially. V

12. In a device of the class described, the combination of: a stationary seat ring, a movable valve member concentrically mounted with respect to theseat ring, means on the valve member for forming a seal with the seat ring, means for moving the valve member axially respect to the seat ring to permit 'gas to flow :through an opening between the valve member and seat ring, said means including a flexible diaphragm having a portion thereof secured to the valve member, the valve member having an outer tapering surface converging axially in the direction of flow, the valve memher having a central chamber communicating with the remote face of the diaphragm, the valve member also having axially facing ports in said outer wall of the valve member communicating with said chamber, and resilient means acting on the diaphragm in an axial direction to close the'seal means.

13. In a device of the class described,:the combination of a stationary horizontal seat ring, a movable valve member concentrically mounted with respect to the seat ring, means on the valve member for forming a seal with the upper end of the seat ring, means for moving the valve member upward away from the seat ring to permit I gas to flow through an opening between the valve memher and seat ring, said means including a flexible diar "phragrn having a portion thereof secured to the valve membenthe valve member having an inwardly tapering downward extending outer surface encircled by the seat ring, the valve member having a central chamber cemmunieating with the upper face of the dia hragm and having downwardly facing ports in said outer wall ofth'e valve member communicating with said chamber, the lower face of the diaphragm communicating with space outside the seat ring, and resilient means acting downward on the diaphragm. i

14. In a device of'the class described, the combination of: a stationary seat ring, a movable valve member concentrically mounted with respect to the seat ring, means on the valve member for forming a seal with the seat ring, means for moving the valve member axially with respect to the seatring to permit gas to flow through an opening between the valve member and seat ring, the valve member having an outer tapering surface converging axially in the direction of flow, the valve member having a central chamber, a series of axially extending circumferentially spaced bosses interrupting said tapering surface, and each'boss having a port in the downstream end thereof communicating with said chamber.

15. In a device of the class described, the combination of: a stationary valve seat, a movable air valve member concentrically mounted with respect to the seat, an annular ring loosely supported upon the periphery of the air valve member and adapted to engage the seat,

stationary means forming a fuel passage extending coaxially of the air valve member, a fuel valve assembly including a fuel valve element mounted formovemen't with the air valve. member and acting to regulate flow of fuel through said fuel passage, the parts being proportioned so that upon closing movement of the air valve member the ring engages the valve seat prior to closing of the fuel passage by the fuel valve element.

References Cited'in the file of this patent UNITED STATES PATENTS v Noyes "flan. 2, 1912 2,788,082 Vanderpoel Apr-'9, 1957 

1. IN A GAS MIXING DEVICE, THE COMBINATION OF: A HOUSEING HAVING A DISCHARGE OPENING, A STATIONARY ANNULAR SEAT RING ON THE HOUSING COMMUNICATING WITH THE OPENING, A MOVABLE VALVE MEMBER HAVING MEANS THEREON ADAPTED TO FORM A SEAL WITH THE SEAT RING, MEANS MOUNTING THE VALVE MEMBER FOR AXIAL MOVEMENT RELATIVE TO THE SEAT RING TO PROVIDE AN ANNULAR FLOW PASSAGE THEREBETWEEN, THE HOUSING HAVING AN AXIAL PASSAGE, A VALVE ELEMENT RESTRICTING FLOW THROUGH THE PASSAGE, AND FLUID-PRESSURE RESPONSIVE MEANS FOR CAUSING SIMULTANEOUS OPENING MOVEMENT OF THE VALVE MEMBER AND THE VALVE ELEMENT UPON REDUCTION OF PRESSURE WITHIN THE DISCHARGE OPENING.
 6. APPARATUS FOR SUPPLYING A MIXTURE OF ATMOSPHERIC AIR AND GASEOUS FUEL TO OPERATE AN INTERNAL COMBUSTION ENGINE, COMPRISING IN COMBINATION: A HOUSING HAVING A DISCHARGE OPENING, A STATIONARY ANNULAR SEAT RING ON THE HOUSING COMMUNICTING WITH THE DISCHARGE OPENING, MOVABLE AIR VALVE MEMBER ENCIRCLED BY THE SEAT RING, MEANS ON THE AIR VALVE MEMBER ADAPTED TO FORM A SEAL WITH THE SEAT RING, MEANS MOUNTING THE AIR VALVE MEMBER FOR AXIAL MOVEMENT RELATIVE TO THE SEAT RING TO PROVIDE AN ANNULAR FLOW PASSAGE FOR AIR INTO THE DISCHARGE OPENING, THE LATTER SAID MEANS INCLUDING A VERTICAL ROD SLIDABLY MOUNTED UPON THE HOUSING, THE HOUSING HAVING AN AXIAL FUEL PASSAGE COMMUNICATING WITH THE DISCHARGE OPENING, THE ROD EXTENDING CENTRALLY THROUGH SAID FUEL PASSAGE, A VALVE ELEMENT ON THE ROD RESTRICTING FLOW THROUGH THE FUEL PASSAGE, AND MEANS RESPONSIVE TO A REDUCTION IN PRESSURE IN THE DISCHARGE OPENING FOR LIFTING THE AIR VALVE MEMBER AND FUEL VALVE ELEMENT TO INCREASE THE RATE OF FLOW OF AIR AND GASEOUS FUEL. 